Tonight with your 13 to 17 year old
The prompt
“Is there a disagreement about fairness that still kind of bugs you, even if it happened a while ago?”
What to listen for
If they launch straight into details, let them vent without fixing it for them, they need to feel like their sense of what's fair actually counts, not just yours.
If they downplay it ("it's stupid, forget it") but still bring it up, that's a sign it matters more than they're letting on, they need to know it's safe to care about something without being told to get over it.
A shrug or "I don't know, nothing really" might just mean it's not fresh in their mind tonight, or it might mean they've learned that bringing up fairness complaints doesn't go anywhere with you, either way, no need to push, just leave the door open.
What this tells you
What still bugs them about fairness shows you where they need their sense of justice taken seriously, not smoothed over.